Sting's performance marked Day Two of a week-long celebration honoring the 50th anniversary of the Fab Four's debut on "The Ed Sullivan Show," which was filmed in the same theater Letterman occupies now.

Beatles Week started Monday with a new rendition of "And I Love Her" from indie duo Broken Bells, and it's set to continue with visits from Lenny Kravitz, the Flaming Lips, and John Lennon's son, Sean Lennon, over the next few days.